1. Field of the Invention
The present invention relates generally to document-feeding apparatus for printers and the like, and more particularly to an improved document feeder using a pressure reduction principle for sheet take-off.
2. Description of the Prior Art
Although vacuum take-off devices for printing and duplicating machines are known in the prior art, such devices have typically utilized complicated mechanical valving in combination with suction rollers, shuttles or other devices which are not only expensive to manufacture but are difficult to maintain. Apparatus such as those disclosed in the United States patents of Hans-Joachim Jahme, U.S. Pat. Nos. 3,861,667 and 3,921,523, overcome some of the problems of the prior art, but require that the paper be folded over nearly 180.degree. as it raps around a suction roller and is discharged. This, of course, gives rise to a number or problems having to do with suction regulation, stiffness of paper, etc.